Manhole inserts

ABSTRACT

Manhole inserts suitable for deployment in a manhole opening of a manhole structure may include a manhole insert bottom. A manhole insert sidewall may extend from the manhole insert bottom. A manhole insert flange may extend from the manhole insert sidewall. A manhole insert gasket may be on the manhole insert flange, The manhole insert gasket may include a solidified, hardened, and cured gasket material having a synthetic silicone elastomer. The manhole insert gasket may be configured to remain exposed on the manhole insert flange prior to deployment of the manhole insert in the manhole opening of the manhole structure.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation of U.S. application Ser. No. 16/252,929, U.S.Pat. No. 11,536,003, filed Jan. 21, 2019, issued Dec. 27, 2022 andentitled “MANHOLE INSERTS AND MANHOLE INSERT GASKET FABRICATIONMETHODS”, which is a divisional of U.S. application Ser. No. 15/427,145,filed Feb. 8, 2017 and entitled “MANHOLE INSERTS AND MANHOLE INSERTGASKET FABRICATION METHODS”, now abandoned, and is related to U.S.application Ser. No. 14/798,546, now U.S. Pat. No. 10,011,971, filedJul. 14, 2015 and entitled MANHOLE INSERTS AND MANHOLE INSERT GASKETFABRICATION METHODS, each of which U.S. application Ser. No. 16/252,929,U.S. application Ser. No. 15/427,145 and U.S. application Ser. No.14/798,546 is hereby incorporated by reference herein in its entirety.

FIELD

Illustrative embodiments of the disclosure generally relate to manholeinserts for closing manholes which overlie subterranean sewer systems.More particularly, illustrative embodiments of the disclosure relate tomanhole inserts having a manhole insert gasket characterized by enhancedsealing capability and longevity and methods of fabricating manholeinsert gaskets on manhole inserts.

BACKGROUND

The background description provided herein is solely for the purpose ofgenerally presenting the context of various illustrative embodiments ofthe disclosure. Aspects of the background description arc neitherexpressly nor impliedly admitted as prior art against the claimedsubject matter.

In sewer systems, manhole structures typically facilitaiC access tosubterranean piping. A typical manhole structure may have a ring-shapedmanhole structure frame which encloses a manhole. A manhole insert ma heplaced in the manhole structure frame to close the manhole and theunderlying sewer system from rainwater and other precipitation. Aremovable manhole cover may be seated in the manhole structure frame tofacilitate access to the manhole and the sewer system.

Manhole inserts having a manhole insert gasket characterized by enhancedsealing capability and longevity and methods of fabricating a manholeinsert gasket on a manhole insert are needed.

SUMMARY

Illustrative embodiments of the disclosure are generally directed tomanhole inserts suitable for deployment in a manhole opening of amanhole structure. An illustrative embodiment of the manhole inserts mayinclude a manhole insert bottom. A manhole insert sidewall may extendfrom the manhole insert bottom. A manhole insert flange may extend fromthe manhole insert sidewall. A manhole insert gasket may be on themanhole insert flange. The manhole insert gasket may include asolidified, hardened, and cured gasket material having a syntheticsilicone elastomer. The manhole insert gasket may be configured toremain exposed on the manhole insert flange prior to deployment of themanhole insert in the manhole opening of the manhole structure.

In some embodiments, the manhole inserts may be fabricated by invertinga manhole insert having a manhole insert flange; forming a manholeinsert gasket by dispensing a liquid gasket material onto the manholeinsert flange along at least one circular dispensing path, the liquidgasket material including a synthetic silicone elastomer; andsolidifying and hardening the gasket material by curing the gasketmaterial to form the manhole insert gasket with the cured gasketmaterial, whereby the manhole insert gasket with the cured gasketmaterial remains exposed on the manhole insert flange prior todeployment of the manhole insert in the manhole opening of the manholestructure.

BRIEF DESCRIPTION OF THE DRAWINGS

Illustrative embodiments of the disclosure will now be described, by wayof example, by reference to the accompanying drawings, in which:

FIG. 1 is a sectional perspective view of an inverted manhole insertaccording to an illustrative embodiment of the disclosure;

FIG. 2 is a bottom view of the illustrative manhole insert;

FIG. 3 is a cross-sectional view taken along section lines 3-3 in FIG. 2;

FIG. 4 is an enlarged sectional view, taken along section line 4 in FIG.3 ;

FIG. 4A is an enlarged sectional view of that illustrated in FIG. 4 ,more, particularly illustrating a typical flanize thickness of a manholeinsert flange on a manhole insert and a typical gasket thickness of amanhole insert gasket on the manhole insert flange;

FIG. 5 is a cross-sectional view taken along section lines 5-5 in FIG. 2;

FIG. 6 is a cross-sectional view of the illustrative manhole insert,seated on a manhole structure shoulder inside a manhole structure framein a manhole structure in typical application of the manhole insert;

FIG. 7 is an enlarged sectional view, taken along section line 7 in FIG.6 ;

FIG. 8 is a functional block diagram which illustrates a typical gasketapplication system suitable for applying a manhole insert gasket on amanhole insert flange of a manhole insert;

FIG. 9 is a top view of a typical gasket application assembly of thegasket application system, preparatory to application of the manholeinsert gasket on the manhole insert flange of the manhole insert;

FIG. 10 is a top view of the gasket application assembly illustrated inFIG. 9 , more particularly illustrating movement of a gasket materialapplication nozzle in a circular dispensing path to dispense a liquidgasket material on the manhole insert flange of the manhole insert intypical application of the manhole insert gasket on the manhole insertflange;

FIGS. 11-13 are enlarged sectional views of the manhole insert flange,illustrating typical sequential application of an inner gasket cord andan outer gasket cord of a manhole insert gasket on the manhole insertflange bottom surface of the manhole insert flange; and

FIG. 14 is flow diagram which illustrates an illustrative embodiment ofa manhole insert gasket fabrication method.

DETAILED DESCRIPTION

The following detailed description is merely exemplary in nature and isnot intended to limit the described embodiments or the application anduses of the described embodiments. As used herein, the word “exemplary”or “illustrative” means “serving as an example, instance, orillustration.” Any implementation described herein as “exemplary” or“illustrative” is not necessarily to be construed as preferred oradvantageous over other implementations. All of the implementationsdescribed below are exemplary implementations provided to enable personsskilled in the art to practice the disclosure and are not intended tolimit the scope of the claims. Moreover, the illustrative embodimentsdescribed herein are not exhaustive and embodiments or implementationsother than those which are described herein and which fall within thescope of the appended claims are possible. Furthermore, there is nointention to be bound by any expressed or implied theory presented inthe preceding technical field, background, brief summary or thefollowing detailed description, As used herein, relative terms such as“upper” and “lower” are intended to be used in an illustrative and not alimiting sense. In some applications, therefore, those elements whicharc identified as “upper” may be located beneath those elements whichare identified as “lower” in the following detailed description. Forpurposes of description herein, such relative terms relate to theposition of the manhole insert as illustrated in FIG. 6 .

Referring initially to FIGS. 1-7 of the drawings, an illustrativeembodiment of the manhole insert is generally indicated by referencenumeral 1. As illustrated in FIG. 6 and will be hereinafter described,the manhole insert 1 is suitably designed and configured to be placed ina manhole opening 24 inside a manhole structure 20. The manholestructure 20 may include a manhole structure frame 21 which encloses themanhole opening 24 and overlies a typically subterranean sanitary sewersystem 26. The manhole insert 1 may prevent rainwater and otherprecipitation and/or floodwater from flowing into the sewer system 26and causing the sewer system 26 to overflow to a ground or roadwaysurface (not illustrated) through the manhole opening 24.

The manhole insert 1 may be generally pan-shaped with a flat or planarmanhole insert bottom 2. In some embodiments, multiple insert stiffeners10 may be formed, shaped, stamped or otherwise provided in the manholeinsert bottom 2. The manhole insert bottom 2 may be fitted withadditional features (not illustrated) such as a pressure relief valve,lift handles and warning tags, for example and without limitation. Amanhole insert sidewall 3 may extend upwardly from an outer edge of themanhole insert bottom 2. A manhole insert flange 4 may extend outwardlyfrom the manhole insert sidewall 3. The manhole insert flange 4 may havea manhole insert flange bottom surface 5. As illustrated in FIG. 3 , amanhole insert interior 8 may be formed by and between the manholeinsert bottom 2 and the manhole insert sidewall 3.

A manhole insert gasket 11 may be provided on the manhole insert flangebottom surface 5 of the manhole insert flange 4. The manhole insertgasket 11 may include at least one annular gasket cord 12, 14. In someembodiments, the manhole insert gasket 11 may include an annular innergasket cord 12 and an annular outer gasket cord 14. Each of the innergasket cord 12 and the outer gasket cord 14 may have a generallysemicircular cross-section. The inner gasket cord 12 and the outergasket cord 14 of the manhole insert gasket 11 may be disposed inconcentric relationship with respect to each other and with respect tothe manhole insert bottom 2 and the manhole insert side wall 3 of themanhole insert 1. An annular inner gasket space 16 may be defined by andbetween the manhole insert side wall 3 and the inner gasket cord 12. Anannular middle gasket space 18 may be defined by and between the innergasket cord 12 and the outer gasket cord 14. An outer gasket space 19may be defined by and between the outer gasket cord 14 and the flangeedge 4 a of the manhole insert flange 4.

As illustrated in FIG. 4A, in some embodiments, the middle gasket space18 may have a middle gasket space width 18 a of about 7 mm. The manholeinsert flange 4 may have a flange thickness 6 of about 1.66 mm. Theinner gasket cord 12 and the outer gasket cord 14 of the manhole insertgasket 11 may each have a gasket thickness 15 of about 1.59 mm.Accordingly, the manhole insert flange 4 and the manhole insert gasket11 may together have a total thickness of about 3.25 mm.

The inner gasket cord 12 and the outer gasket cord 14 of the manholeinsert gasket 11 may be fabricated of a material and according to aprocess which will be hereinafter described. In some embodiments, theinner gasket cord 12 and the outer gasket cord 14 of the manhole insertgasket 11 may be fabricated by application and curing of a liquid gasketmaterial which includes a synthetic silicone elastomer. The manholeinsert gasket 11 may be compatible with the material of which themanhole insert 1 is fabricated to form a long-lasting bond under wet ordry conditions. In some embodiments, the manhole insert gasket 11 mayhave the following physical properties:

-   -   Tensile strength: 335 psi—ASTM D412 Elongation (400-600%)—ASTM        D412    -   Shore Hardness: 25 Shore A—ASTM D2240    -   Adhesion to Stainless: 580 psi—ASTM D4541/D7234

In some embodiments, the manhole insert gasket 11 may be fabricated of733 glass and metal sealant silicone black which is available from DowCorning Corp. The 733 glass and metal sealant is a one-component,non-slumping silicone paste which offers an unprimed adhesion, moisturecure, flexibility and resistance to extreme temperatures, moisture,weathering and vibrations. The 733 glass and metal sealant has a curetime of 24 hours @ room temperature, elongation of 500%, hardness of25A, a service temperature of −57° C.-177° C., specific gravity of1.04@25° C., tack free time of 15 min. and tensile strength of 335 psi.

Referring next to FIGS. 6 and 7 of the drawings, in typical application,the manhole insert l is placed in the manhole opening 24 with themanhole insert gasket 11 seated on the manhole shoulder 22 in themanhole structure frame 21 of the manhole structure 20. Accordingly, asillustrated in FIG. 7 , the inner gasket cord 12 and the outer gasketcord 14 of the manhole insert gasket 11 may be compressed between themanhole structure shoulder 22 of the manhole structure 20 and themanhole insert flange 4 of the manhole insert 1. The inner gasket space16, the middle gasket space 18 and the outer gasket space 19 mayaccommodate the inner gasket cord 12 and the outer gasket cord 14 aseach expands outwardly under the weight of the manhole insert flange 4against the manhole structure shoulder 22. A manhole cover 28 (FIG. 6 )may be placed on the manhole structure frame 21 to close the manholeopening 24 above the manhole insert 1.

During heavy rain and other precipitation, the manhole insert 1 preventsrainwater and other precipitation and/or floodwater from entering thesewer system 26 through the manhole opening 24. This in turn, preventsthe sewer system 26 from overflowing through the manhole opening 24 tothe ground or roadway surface. The manhole insert gasket 11 imparts aliquid-tight seal between the manhole insert flange 4 and the underlyingmanhole structure shoulder 22 to prevent seepage of water and/orsewerage between the manhole insert flange 4 and the manhole shoulder22. It will he appreciated by those skilled in the art that the manholeinsert gasket 1 exhibits enhanced liquid sealing characteristics as wellas enhanced longevity to prevent or reduce the necessity or frequency ofreplacing the manhole insert 1 or the manhole insert gasket 11 on themanhole insert flange 4. Moreover, the inner gasket cord 12 and theouter gasket cord 14 ensure continued sealing capability of the manholeinsert gasket 11 since in the event that one is compromised, the othermay remain intact. This expedient enhances the longevity al the manholeinsert I in the manhole structure 20.

Referring next to FIGS. 8-13 of the drawings, a typical gasketapplication system 34 which is suitable for application of the manholeinsert gasket 11 to the manhole insert flange 4 of the manhole insert 1is illustrated in FIGS. 8-10 . The gasket application system 34 mayinclude a gasket application assembly 35. As illustrated in FIGS. 9 and10 , in some embodiments, the gasket application assembly 35 may includea pair of generally elongated, parallel, spaced-apart assembly siderails 36. An elongated front rail connecting member 37 and an elongatedrear rail connecting member 38 may extend between the assembly siderails 36 in parallel, spaced-apart relationship to each other. A pair ofelongated, parallel, spaced-apart assembly rail stabilizing members 40may extend between the front rail connecting member 37 and the rear railconnecting member 38. As further illustrated in FIGS. 9 and 10 , intypical application of the gasket application system 34, which will behereinafter described, the assembly rail stabilizing members 40 maysupport an insert support platform 68. The manhole insert 1 may beinverted and placed on the insert support platform 68 for fabrication ofthe manhole insert gasket 11 on the manhole insert flange bottom surface5 of the manhole insert flange 4 typically in a manner which will behereinafter described.

An elongated nozzle carriage rail 42 may he suitably adapted tobi-directionally traverse the assembly side rails 36 between the frontrail connecting member 37 and the rear rail connecting member 38.Accordingly, a pair of nozzle carriage rail brackets 43 may beconfigured to bi-directionally traverse the respective assembly siderails 36, Each nozzle carriage rail bracket 43 may be fitted withcarriage rollers 44 which engage the corresponding assembly side rail36. A carriage rail motor 46 may be provided on one of the nozzlecarriage rail brackets 43. The carriage rail motor 46 may drivinglyengage a drive roller 45 which, in turn, drivingly engages the assemblyside rail 36. Accordingly, the nozzle carriage rail 42 maybi-directionally traverse the assembly side rails 36 responsive tooperation of the carriage rail motor 46.

A nozzle assembly 50 may be suitably adapted to bi-directionallytraverse the nozzle carriage rail 42 between the assembly side rails 36.The nozzle assembly 50 may include a nozzle carriage 51 which may hefitted with carriage rollers 52 and a drive roller 53 that engage thenozzle carriage rail 42. A nozzle carriage motor 54 may drivingly engagethe drive roller 53 such that the nozzle assembly 50 bi-directionallytraverses the nozzle carriage rail 42 responsive to operation of thenozzle carriage motor 54.

A gasket material application nozzle 56 may he provided on the nozzlecarriage 51 of the nozzle assembly 503. As illustrated in FIG. 8 , apump 62 may be disposed in fluid communication with the gasket materialapplication nozzle 56. The liquid gasket material 63 which will be usedto form the manhole insert gasket 11 may he disposed in fluidcommunication with the pump 62. A CPU 60 having user controls 61 may beoperably connected to the pump 62. Accordingly, as illustrated in FIG.10 , in fabrication of the manhole insert gasket 1, as will hehereinafter described, the CPU 60 may operate the pump 62 to pump theliquid gasket material 63 to the gasket material application nozzle 56at a selected rate and volume, typically responsive to programmed inputfrom the user controls 61. The liquid gasket material 63 may bedispensed from the gasket material application nozzle 56 onto themanhole insert flange bottom surface 5 of the manhole insert flange 4 asthe gasket, material application nozzle 56 traverses a selected circulardispensing path 58 (FIG. 10 ) which defines the circumference of thecorresponding inner gasket cord 12 and the outer gasket cord 14 of themanhole insert gasket 11.

As further illustrated in FIG. 8 , the CPU 60 may further he operablyconnected to the carriage rail motor 46 and to the nozzle carriage motor54 on the nozzle carriage 51 of the nozzle assembly 50. Accordingly,typically responsive to programmed input from the user controls 61, theCPU 60 may operate the carriage rail motor 46 and the nozzle carriagemotor 54 in conjunction with each other in such a manner that the nozzlecarriage 51 of the nozzle assembly 50 traverses the manhole insertflange 4 of the manhole insert 1 in the selected circular dispensingpath 58 and at a selected speed for deposition of the inner gasket cord12 and the outer gasket cord 14 of the manhole insert gasket 11 onto themanhole insert bottom surface 5 of the manhole insert flange 4.

In typical fabrication of the manhole insert gasket 11 on the manholeinsert 1, the manhole insert 1 may be inverted and placed on the insertsupport platform 68 of the gasket application assembly 35, with themanhole insert flange bottom surface 5 facing upwardly, as illustratedin FIG. 9 . The liquid gasket material 63 (FIG. 8 ) may be prepared andpoured or otherwise placed into a suitable vessel (not illustrated)which is disposed in fluid communication with the pump 62. Via the usercontrols 61, the CPU 60 may he programmed to operate the pump 62 at aselected speed to facilitate dispensing of the liquid gasket material 63onto the manhole insert flange 4 at a selected volume and rate forfabrication of the respective inner gasket cord 12 and the outer gasketcord 14 of the manhole insert gasket 11. The CPU 60 may additionally beprogrammed to operate the carriage rail motor 46 and the nozzle carriagemotor 54 of the nozzle carriage 51 at a selected rate and in a selecteddirectional pattern or sequence to facilitate traversal of the gasketmaterial application nozzle 56 along the corresponding circulardispensing path 58 (FIG. 10 ) for sequential deposition of the liquidgasket material 63 in fabrication of the inner gasket cord 12 and theouter gasket cord 14 on the manhole insert flange bottom surface 5 ofthe manhole insert flange 4, as illustrated in FIGS. 11-13 .

After it is dispensed on the manhole insert flange 4, the liquid gasketmaterial 63 may be allowed to cure and solidify. In some applications,talcum powder or the like (not illustrated) may be applied to thesurface of the inner gasket cord 12 and outer gasket cord 14 toneutralize stickiness on the manhole insert gasket 11 after the easketmaterial 63 cures. After each of the inner gasket cord 12 and the outergasket cord 14 cures, the manhole insert 1 may be removed from theinsert support platform 68. The manhole insert 1 may subsequently beinstalled in a manhole structure 20, as was heretofore described withrespect to FIG. 6 .

Referrina next to FIG. 14 of the drawings, a flow diagram whichillustrates an illustrative embodiment of a manhole insert gasketfabrication method is generally indicated by reference numeral 100. AtStep 102, a manhole insert may be placed in an inverted position. Themanhole insert may include manhole insert bottom, a manhole insertsidewall extending from the manhole insert bottom and a manhole insertflange extending from the manhole insert sidewall. At Step 104, a liquidgasket material may be dispensed onto a bottom surface of a manholeinsert flange along a first circular dispensing path to form an innergasket cord of a manhole insert gasket. The liquid gasket material mayinclude a synthetic silicone elastomer. At Step 106, the liquid gasketmaterial may be dispensed onto the bottom surface of the manhole insertflange along a second circular dispensing path to form an outer gasketcord of the manhole insert gasket. At Step 108, the liquid gasketmaterial of the inner gasket cord and the outer gasket cord may becured. The manhole insert, gasket may he subsequently installed in amanhole structure.

While the preferred embodiments of the disclosure have been describedabove, it will be recognized and understood that various modificationscan be made in the disclosure and the appended claims are intended tocover all such modifications which may fall within the spirit and scopeof the disclosure.

What is claimed is:
 1. A manhole insert suitable for deployment in amanhole opening of a manhole structure. comprising: a manhole insertbottom; a manhole insert sidewall extending from the manhole insertbottom a manhole insert flange extending from the manhole insertsidewall; and a manhole insert gasket on the manhole insert flange andcomprising a solidified, hardened, and cured gasket material comprisinga synthetic silicone elastomer, the manhole insert gasket configured toremain exposed on the manhole insert flange prior to deployment of themanhole insert in the manhole opening of the manhole structure.
 2. Themanhole insert of claim 1 wherein the manhole insert gasket comprises atleast one annular gasket cord.
 3. The manhole insert of claim 2 whereinthe at least one annular gasket cord has a semicircular cross-section.4. The manhole insert of claim 2 wherein the at least one annular gasketcam has a gasket thickness of 1.59 mm.
 5. The manhole insert of claim 2wherein the at least one annular gasket cord comprises an inner gasketcord and an outer gasket cord.
 6. The manhole insert of claim 5 furthercomprising an annular inner gasket space between the manhole insertsidewall and the inner gasket cord and an annular middle gasket spacebetween the inner gasket cord and the outer gasket cord.
 7. The manholeinsert of claim 6 wherein the middle gasket space has a middle gasketspace width of 7 mm.
 8. The manhole insert of claim 1 wherein thesynthetic silicone elastomer has a tensile strength of 335 psi and anelongation of from 400% to 600%.
 9. A manhole insert suitable fordeployment in a manhole opening of a manhole structure, comprising: amanhole insert bottom; a manhole insert sidewall extending from themanhole insert bottom; a manhole insert flange extending from themanhole insert sidewall; and a manhole insert gasket having a discreteannular inner gasket cord on the manhole insert flange and a discreteannular outer gasket cord on the manhole insert flange in spaced-apartrelationship to the inner gasket cord, the outer gasket cordstructurally distinct from the inner gasket cord, the inner gasket cordand the outer gasket cord of the manhole insert gasket each comprising asolidified, hardened, and cured gasket material comprising a syntheticsilicone elastomer, the manhole insert gasket configured to remainexposed on the manhole insert flange prior to deployment of the manholeinsert in the manhole opening of the manhole structure.
 10. The manholeinsert of claim 9 wherein each of the inner gasket cord and the outergasket cord has a semicircular cross-section.
 11. The manhole insert ofclaim 9 wherein each of the inner gasket cord and the outer gasket cordhas a gasket thickness of 1.59 mm.
 12. The manhole insert of claim 9further comprising an annular inner gasket space between the manholeinsert sidewall and the inner gasket cord and an annular middle gasketspace between the inner gasket cord and the outer gasket cord, andwherein the middle gasket space has a middle gasket space width of 7 mm.13. The manhole insert of claim 9 wherein the synthetic siliconeeiastomer has a tensile strength of 335 psi and an elongation from 400%to 600%.
 14. The manhole insert of claim 9 wherein the manhole insertgasket has a Shore Hardness of 25 and an Adhesion to Stainless Steel of580 psi.
 15. A manhole insert having a manhole insert flange andsuitable for deployment in a manhole opening of a manhole structure, themanhole insert fabricated by: inverting the manhole insert having themanhole insert flange; forming a manhole insert gasket by dispensing aliquid gasket material onto the manhole insert flange along at least onecircular dispensing path, the liquid gasket material including asynthetic silicone elastomer: and solidifying and hardening the gasketmaterial by curing the gasket material to form the manhole insert gasketwith the cured gasket material, whereby the manhole insert gasket withthe cured gasket material remains exposed on the manhole insert flangeprior to deployment of the manhole insert in the manhole opening of themanhole structure.
 16. The manhole insert of claim 15 wherein themanhole insert gasket comprises an annular inner gasket cord and anannular outer gasket cord.
 17. The manhole insert of claim 16 whereineach of the inner gasket cord and the outer gasket cord has asemicircular cross-section.
 18. The manhole insert of claim 16 whereineach of the inner gasket cord and the outer gasket cord has a gasketthickness of 1.59 mm.
 19. The manhole insert of claim 15 wherein thesynthetic silicone elastomer has a tensile strength of 335 psi and anelongation from 400% to 600%.
 20. The manhole insert of claim 15 whereinthe manhole insert gasket has a Shore Hardness of 25 and an Adhesion toStainless Steel of 580 psi.